[Code of Federal Regulations]
[Title 14, Volume 1]
[Revised as of January 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 14CFR25.111]

[Page 355-356]
 
                     TITLE 14--AERONAUTICS AND SPACE
 
CHAPTER I--FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION
 
PART 25_AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES--
Table of Contents
 
                            Subpart B_Flight
 
Sec.  25.111  Takeoff path.

    (a) The takeoff path extends from a standing start to a point in the 
takeoff at which the airplane is 1,500 feet above the takeoff surface, 
or at which the transition from the takeoff to the en route 
configuration is completed and VFTO is reached, whichever 
point is higher. In addition--
    (1) The takeoff path must be based on the procedures prescribed in 
Sec.  25.101(f);

[[Page 356]]

    (2) The airplane must be accelerated on the ground to VEF, at which 
point the critical engine must be made inoperative and remain 
inoperative for the rest of the takeoff; and
    (3) After reaching VEF, the airplane must be accelerated to 
V2.
    (b) During the acceleration to speed V2, the nose gear 
may be raised off the ground at a speed not less than VR. However, 
landing gear retraction may not be begun until the airplane is airborne.
    (c) During the takeoff path determination in accordance with 
paragraphs (a) and (b) of this section--
    (1) The slope of the airborne part of the takeoff path must be 
positive at each point;
    (2) The airplane must reach V2 before it is 35 feet above the 
takeoff surface and must continue at a speed as close as practical to, 
but not less than V2, until it is 400 feet above the takeoff surface;
    (3) At each point along the takeoff path, starting at the point at 
which the airplane reaches 400 feet above the takeoff surface, the 
available gradient of climb may not be less than--
    (i) 1.2 percent for two-engine airplanes;
    (ii) 1.5 percent for three-engine airplanes; and
    (iii) 1.7 percent for four-engine airplanes; and
    (4) Except for gear retraction and automatic propeller feathering, 
the airplane configuration may not be changed, and no change in power or 
thrust that requires action by the pilot may be made, until the airplane 
is 400 feet above the takeoff surface.
    (d) The takeoff path must be determined by a continuous demonstrated 
takeoff or by synthesis from segments. If the takeoff path is determined 
by the segmental method--
    (1) The segments must be clearly defined and must be related to the 
distinct changes in the configuration, power or thrust, and speed;
    (2) The weight of the airplane, the configuration, and the power or 
thrust must be constant throughout each segment and must correspond to 
the most critical condition prevailing in the segment;
    (3) The flight path must be based on the airplane's performance 
without ground effect; and
    (4) The takeoff path data must be checked by continuous demonstrated 
takeoffs up to the point at which the airplane is out of ground effect 
and its speed is stabilized, to ensure that the path is conservative 
relative to the continous path.

The airplane is considered to be out of the ground effect when it 
reaches a height equal to its wing span.
    (e) For airplanes equipped with standby power rocket engines, the 
takeoff path may be determined in accordance with section II of appendix 
E.

[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as amended by Amdt. 25-6, 30 
FR 8468, July 2, 1965; Amdt. 25-42, 43 FR 2321, Jan. 16, 1978; Amdt. 25-
54, 45 FR 60172, Sept. 11, 1980; Amdt. 25-72, 55 FR 29774, July 20, 
1990; Amdt. 25-94, 63 FR 8848, Feb. 23, 1998; Amdt. 25-108, 67 FR 70826, 
Nov. 26, 2002; Amdt. 25-115, 69 FR 40527, July 2, 2004]